Diastolic Electrocardiographic Parameters Predict Implantable Device Detected Asymptomatic Atrial Fibrillation

Abstract

Background: Atrial fibrillation is the most commonclinically significant arrhythmia. It is now establishedthat atrial high-rate episodes are highly correlated withatrial fibrillation.Aims: To investigate the relation between diastolicelectrocardiographic parameters and subclinical atrialfibrillation detected by cardiac implantable electronicdevices.Study Design: Ccross-sectional study.Methods: Atotal of 203 patientswho had a dual-chamber,rate-modulated pacing pacemaker implanted due tosinus node dysfunction were prospectively enrolled inthis study. Atrial high-rate episodes were defined as anylasting more than 5 min with an atrial rate of >=220 beatsper minute during the previous year. Patient groups werecategorized on the basis of pacemaker interrogation asthe absence of atrial high-rate episodes [atrial high-rateepisodes (-)] and the presence of atrial high-rate episodes[atrial high-rate episodes (+)]. Episodes related toatrial over sensing were excluded. Twelve-lead surfaceelectrocardiography was independently analyzed by twoexperienced readers for the measurement of diastolicelectrocardiography parameters.Results: Among 203 patients (mean age: 67.5±9.1,60.1% male), 51 (25.1%) with atrial high-rate episodeswere defined as group 1 and 152 (74.9%) without atrialhigh-rate episodes were defined as group 2. Both groupswere similar in terms of demographic characteristicsand cardiovascular risk factors. Tend-Q and Tend-Pwere significantly longer in group 2. PQ intervalwas statistically longer in group 1. Corrected QTinterval was significantly longer in group 1. Diastolicelectrocardiography index, heart rate and PQ and QTintervals were the only independent predictors of atrialhigh-rate episodes in patients with dual pacemakers inmultivariate analysis.Conclusion: Abnormal diastolic electrocardiographyparameters are powerful predisposing factors forthe initiation of incident atrial fibrillation. Diastolicelectrocardiography parameters and a novel diastolicindex predict atrial high-rate episodes. Evaluating theseparameters enables clinicians to identify patients whoare at high risk and who may benefit from prophylactictreatment.